Various semiconductor devices are mounted in an electronic apparatus. The semiconductor devices each include a semiconductor element which performs various calculations and a semiconductor device substrate for supplying power and signals to the semiconductor element.
Power supply to the semiconductor element is performed using a ground pattern and a power supply pattern provided in the semiconductor device substrate. However, if the potentials of these patterns, or the power supply voltage, fluctuate, the semiconductor element malfunctions.
Thus, in such a type of semiconductor device substrate, a decoupling capacitor is provided between the ground pattern and the power supply pattern, and the fluctuation of the power supply voltage is absorbed by the decoupling capacitor to stabilize the power supply voltage.
In a case where the decoupling capacitor is provided as described above, it is preferable to reduce noise occurring in the semiconductor element and the semiconductor device substrate.
Patent Document 1: Japanese Laid-open Patent Publication No. 2009-200470
Patent Document 2: Japanese Laid-open Patent Publication No. 2008-227387